A conventional sheet-feed scanner includes a scanner 11 and a feeder 12, as shown in FIG. 1. An article is automatically fed through a passage 13 between the scanner 11 and the feeder 12 to be scanned by way of the frictional force generated when rollers 111 of the scanner 11 and rollers 121 of the feeder 12 rotate, and therefore the whole article can be scanned. When the article is passing through the passage 13, a light source 112 included in the scanner 11 emits a light on the surface of the article and the light is then reflected from the surface of the article to a CCD 113 of the scanner 11 which converts the reflected light into an electric signal. The electric signal is processed by a circuit in the scanner 11 to have the contents of the scanned article shown on the monitor of the computer or printed by a printer.
The aforementioned conventional sheet-feed scanner only possesses a light source installed in the scanner 11 so that the scanner 11 cannot receive the reflected light to perform signal-conversion in the CCD 113 if the article is light-penetrating, e.g. transparent, rather than light-reflecting. Therefore, the conventional scanner can only perform a reflection-mode scanning, and more particularly, it can only allow some specific kinds of articles, e.g. a name card, a picture, a credit card, etc., to be scanned.